Vegan Steak Sandwich With Lemon Garlic Aioli

vegan steak sandwich

The Mouth-Watering Vegan Steak Sandwich You’ll Want to Eat Every Single Day

The road to making these vegan steak sandwiches was not an easy one, y’all. Remember my mushroom “asada” tacos? I was inspired by them to transform mushrooms into yet another delish, “meaty” recipe. I’ve been seeing a lot of mushroom recipes on my Instagram feed lately, and I had to follow suit. Any way to limit my consumption of meat substitutes is a win to me!

But this actual recipe came about from an epic fail I had the other day — I wanted to try making my own vegan steak strips, made out of portobellos, to post here, but the marinade went all wrong. This was my first time using liquid aminos (I bought the Bragg’s brand), and I didn’t know the flavor profile or the common uses (it just smelled really good and savory). So, I made my marinade with both liquid aminos and soy sauce….yikes. Those mushrooms were SO salty, I felt bad about even cooking them!

In an effort to redeem myself, I knew I had to try these vegan steaks again. I couldn’t let my silly mistake get to me, so I thought, how can I make these steak strips the best thing I’ve ever made? Well, friends, it’s all about the sandwich.

vegan steak sandwich
Lots of rich and savory mushroom steak strips tastes the best with some caramelized onions and melted cheese.

Typically, I’m not much of a sandwich gal. I get bored easily by the makeup of them, and they don’t really satisfy me. But, I’m always down for a nice sandwich from a restaurant — maybe it’s the bread, or the fact I didn’t have to make it for myself. Regular sliced bread was not an option here, friends. I bought an herbed ciabatta from Sprouts (for $0.99 a bag! 3 breads a bag!) because why not?

Anyways, I set about to make a cheesy, savory, filling vegan steak sandwich to get over my fear of oversalting. And I think it’s safe to say I succeeded! These mushroom slices can be made into a vegan cheesesteak, tacos, or on its own with some sides. This is definitely one sandwich I could have every day…

vegan steak sandwich

Vegan Steak Sandwich with Lemon Garlic Aioli

Caramelized onions, savory mushroom strips, and a lemon garlic spread is the combination we all needed to seriously up our sandwich game.
5 from 1 vote
Prep Time 20 mins
Cook Time 20 mins
Course Entree, Main Course
Cuisine American
Servings 6 sandwiches


Lemon Garlic Aioli

  • ½ cup vegan mayo
  • 1 lemon zested and juiced
  • 2 tbsp minced garlic roasted
  • 1 tsp pepper
  • ½ tsp salt
  • ¼ tsp onion powder
  • ¼ tsp cayenne pepper

Sandwich Ingredients

  • 6 herbed ciabatta squares
  • 2 tbsp olive oil or butter
  • 5 portobello mushrooms sliced and stems removed
  • ½ onion sliced
  • ½ cup liquid aminos
  • 5 tbsp vegan worcestershire sauce
  • 6 slices vegan provolone cheese
  • 1 cup baby spinach
  • 1 tsp pepper
  • ¼ tsp salt


  • Prepare the aioli — start by putting the garlic in an unoiled pan and roast on medium heat until slightly browned and fragrant
  • Mix the garlic into the mayo, and add lemon juice/zest and spices. Set aside
  • Slice the onion and cook in a pan with butter or oil. Stir occasionally until softened and caramelized. Transfer to a bowl and set aside
  • Slice the portobellos and add them to the pan where the onions were. Add the liquid aminos, worcestershire sauce, and lemon juice
  • Gently stir the mushrooms to help them shrink and make sure all of the pieces are coated in the sauce. Cover and simmer for 10 min
  • After 10 min, add the onions back into the pan with the mushrooms and stir. Continue to simmer for 5 more min. and then change the heat to the lowest setting to keep warm
  • Cut each ciabatta in half and spread aioli on cut side of both halves
  • In a clean, unoiled pan on low heat, put the bottom piece of bread cut side down to toast
  • Flip the piece of bread and add a slice of cheese. Cover the pan to melt the cheese
  • Take that bread slice out and add the top to the pan. On the cheesy slice, scoop the onion and mushroom filling
  • Top with fresh spinach and add the top slice of bread. Serve with additional mushroom sauce if desired


  • If you want to get a little ~crazy~, add another slice of cheese to the toasted top piece of bread. OR you can even add cheese to the mushroom and onion mixture — just beware of the messy eating that’ll ensue.
  • You don’t have to use ciabatta — feel free to use any type of bread. And if you have leftovers, the mushroom filling would be really good with some rice.
  • The filling is almost better the second day around, because it soaks up a lot more of the sauce, so the filling is definitely something you can make ahead of time. 
Keyword cheap, easy, mushroom, sandwich, savory

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  1. 5 stars
    I’ve tried a few of your recipes and this one is my favorite 😍:)

    I ate 2 in a row ❤️

  2. […] my own vegan version of ceviche. Nothing would sound good on those 100º days — we could have vegan steak sandwiches or a quick bowl of pasta, but obviously no one wanted to turn the stove on. The only cold meal we […]

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